Posted
by
Zonk
on Saturday February 16, 2008 @12:23AM
from the crafty-devs dept.

Dean Garfield writes "An article at TorrentFreak notes that several BitTorrent developers have proposed a new protocol extension with the ability to bypass the BitTorrent interfering techniques used by Comcast and other ISPs. 'This new form of encryption will be implemented in BitTorrent clients including uTorrent, so Comcast subscribers are free to share again. The goal of this new type of encryption (or obfuscation) is to prevent ISPs from blocking or disrupting BitTorrent traffic connections that span between the receiver of a tracker response and any peer IP-port appearing in that tracker response, according to the proposal.'"

Why wait 10-15 years? Jump on the bandwagon and make impossible predictions about the near future.

In 10-15 years, p2p will stand for Person to Person, as we will have placed the computers inside our heads, we will share thoughts. No more picture based porn, when you "download" the new porn, it will appear as you in it. And you will not only get to see/heard, but also smell, taste, and feel. More importantly, cyber-sex will be much more like real sex, as a virtual world will be just as real as the real world.

Oh, and in 20 years legislation will have been past severely restricting this new technology to anyone under 21 years of age, and in some states, cyber-anal-sex will be a capital offense. In 23 years, Comcast will start 'degrading' this new service for due to 'QoS' concerns. After a few million people have their virtual parters turn into cows during virtual sex, a riot breaks out leaving America as a second world nation.

Wouldn't the riots break out as soon as people started spamming goatse in this new brave virtual sex world?
Also, how can I prevent virtual herpes from all these virtual whores I'm virtually sleeping with?

Unless one side suddenly blows away the other, I don't see this ending. It may breed innovation, but said innovation only seems useful for this one problem.

As far as I followed, most Bittorrent based "inventions" were done because of attacks by dark companies (media defender), fake seeders etc. Comcast is practically DOS attacking their own customers so someone finds a workaround for it. If it is good enough, all those bittorrent clients will adopt it in no time and they will end up with horrible publicity, paranoid customers, FCC investigation for nothing. Technical karma:)

Obviously, you didn't understand what I said: nothing you do on your end would matter, because the computer on the other end of the connection -- the one you're downloading from or uploading to -- will still receive the fake RST packet that Comcast sends them in your name. In other words, even non-Comcast-users would have to cooperate in order for it to work, and that's not likely to happen (because RST packets are, otherwise, a good thing).

Comcast's bittorrent filtering has almost certainly cost them money in the form of hardware and software to implement it. If continual updates to the protocol make it more difficult and expensive to filter, then theres always the chance that ISPs could decide it's actually a better investment in the long run to upgrade their networks, rather than upgrade their filtering. That could just be wishful thinking, tho...

Or they could just do the sensible thing, cut out all the bullshit "unlimited" advertising (which should be against the law anyways) and start selling customers a set block of gigabytes, with an over-limit charge per gig, just like the dialup ISPs did with time online in the olden days. That's what I did at the small ISP I worked for. I wrote and maintained the billing software, and just sucked in usage stats off our Radius servers once an hour. The system was even set up to send out an email when a user was close to his gigabyte limit letting him know that the meter was going to start running and what the charge per gig was.

We tried shaping P2P traffic, and it just annoyed customers, and annoying customers is not exactly a long-term strategy for success.

If they ever do manage to completely block P2P then they might find themselves looking at a bunch of customers who only want 300kbit connections instead of 20mbits. What are they going to do? Slash their prices to the same as the small ISPs who can offer cheaper/slower connections? I think not.

My guess is they'll do what they do now, and charge the same price for ANY connection that doesn't require dialing in with a modem.90% of people with broadband probably only need 300kbit anyway, for browsing the Net and checking email. But they end up paying $40+/mo for faster, "unlimited" connections, because cable companies have monopolies or oligopolies on access and they don't offer low-bandwidth plans.

"Or they could just do the sensible thing, cut out all the bullshit "unlimited" advertising and start selling customers a set block of gigabytes."

I can assure you, you don't want this. You assume that the ISP's are going to give you a "reasonable" block of data to transfer on a monthly basis and a reasonable price - they are not. They will use this pricing scheme to "extract value" from their customer base in the form of quotas that are properly tiered so as to be just below the common usage tier. The result will be many customers need to go a step higher, and are charged more, for considerably less than they had access to before. Do you really want to worry about whether the next movie you get off of iTunes is going to pop your quota? Or the next stream you setup?

Honestly, bandwidth in the US is what is causing a great deal of innovation at the moment - look at iTunes and Netflix now offering entire movies as either downloads or streaming. Caps will only stifle the adoption and innvoation of this type of technolgy. Customers will think twice about the double cost of streaming a video - the cost to their cap, and the cost of the service. There are I'm sure other bandwith based applications out there that we have not even thought of.

The answer is just in disclaiming that running certain types of services like bittorrent coupled with excessive transfer on a connection can lead to service degredation, not termination. They just need to put a process in place to handle this situation. Time warner claims that "5% of their customers use 50% of their bandwidth" - well - that seems pretty damn easy to fix doesn't it? Exceed a certain monthly transfer rate, send out a warning via e-mail - usage continues - put a cap that is far lower than their original amount.

In addition they don't really say that they are running out of bandwidth, so I'm not sure I see where the problem is.

In addition they don't really say that they are running out of bandwidth, so I'm not sure I see where the problem is.

They're not... they're running out of shareholder satisfaction. Their customers are demanding more capacity, and their shareholders are demanding more money now. The two are diametrically opposed, with the ISP squarely in the middle. Either we adjust our expectations downward, or the shareholders do.

Reportedly most of it comes from botnets:Insecure machines that were taken over by hackers and whose clueless owners did not notice anything. Or even don't care.

Now if ISPs start selling traffic by the gigabyte (again - it was not uncommon a few years ago), the owner of those spam-slaves would notice it on their internet bills. At that point, I think securing one's machine would become a lot more popular and the botnets would shrink. Overall result:less spam and DDOS attacks.

Considering the inbound hacking attempts, my father still has a 2 GByte/month plan and so far I've heard no complaints about suddenly increasing bills. So it seems to be not that much.

All you would need to do to circumvent that is use something stateless like UDP. If they want to limit UDP to something like no more than 100 different IP's sending you packets within a set time period, they just created an amazingly simple DoS attack against all of their customers.

Even without udp you could just make sure you fully close all your connections as soon as possible, if not sooner (i.e kill slow clients to make room for fast ones).

Also setting this too low could limit legit use, like when you start up your computer and have a burst of all your software checking for updates, checking for mail, rss feeds/podcasts/etc going off, all your IM clients connecting to their various servers, etc.

The bittorent devs have the upper hand, at least for the forseable future, because of strong crypto like AES, Serpent, and Twofish for symmetric session traffic and strong public key crypto like RSA to handle the handshakes and symmetric key exchanges. The only response of the ISP is to try and automate Man in the Middle (MITM), but that will be extremely difficult and expensive to implement in practice. Remember that Comcast was throttling bandwidth to cut costs on network upgrades so why would they spend exponentially more on new specialized crypto hardware and software to MITM the handshakes on bittorent sessions if they are too cheap to even upgrade their network? Unless and until there are substantial advances in cryptanalyis (as far as I know there have been no substantial improvements on known attacks in recent years, minor optimizations here and there but not enough to really put a dent in the crypto) or quantum computers become cheap and practical, encryption will provide a very strong defense against network filtering, particularly when it is combined with port randomization. That is why it is in the best Interests of Comcast and other ISPs NOT to escalate by engaging in packet filtering. They will only hasten the development of bittorent clients with strong crypto, as they are doing here, AND draw attention to these new "super" clients that are not "slow".

Remember that Comcast was throttling bandwidth to cut costs on network upgrades so why would they spend exponentially more on new specialized crypto hardware and software to MITM the handshakes on bittorent sessions if they are too cheap to even upgrade their network?

That's a very important point. Comcast is going to have to spend $X to make their network tolerable, either by buying blocking P2P and other bandwidth-hungry application, or by expanding capacity. The first method gets them a nice, controlled, slow network and the hatred of all their potential customers. The second gives them a wild-and-woolly, fast network their customers love (and therefore more customers). So, again, given $X: do you invest it to lose business or gain business? That's really the choice here.

Given Comcast, they'll probably use it to put ultrasonic speakers on their modems so that teens don't want to use them, then five years lateer ask Congress for a bailout because they're uncompetitive.

Most blocking systems use traffic analysis to block encrypted protocols, even the ones pretending to be something else. There's no way you can confuse p2p sharing with normal browsing if you look at the pattern of data flows.

That's nice, except that blocking encrypted protocols blocks quite a bit more than BitTorrent. . . Secure banking over SSL, SSH, VPNs, and a whole plethora of other protocols. Unless an ISP is willing to go from Internet Service Provider to Web Browsing Service Provider, it would be foolish to block encrypted protocols.

Why not? Sure the connection between client and bank wouldnt, but what about between banks? thats a hell of a lot more data being transfered back and forth... not to mention that its sort of the same concept, a bunch of peers all sharing data, some already contain the same data, some dont...But that doesnt mean I dont agree with you, with only banks specifically though, im sure they would have re-created the banks networks to avoid this dilemma... only that by traffic analysis alone, I could easily see it f

Nobody is going to block all encrypted protocols, that's stupid. They identify the application that is using encryption by looking at the shape of the traffic flows. p2p apps open tons of connections, exchange about equal amount of data both ways, and have a distinct negotiation phase.

I think you may have missed the point of the GP post.The point wasn't to block encrypted traffic just because it is encrypted. It would be to do traffic shaping, so that a connection generating dozens or hundreds of simultaneous encrypted connections to different destination IP's might be targeted; it is a traffic pattern would most likely be generated by a P2P program and not by normal internet use by a family.

AFAIK, Rogers in Canada is actually doing that. I'm a subscriber... Encrypted traffic causes slowdown everywhere on the net, including the torrents. If I do a torrent/unencrypted, it gets caught by the torrent filter, and my connection slows down again. Some tweaking makes it a little better, but it's difficult to deal with such a massive blow to my net speed (cut down to roughly 1/8th of its normal speed).

I think the idea here is to stop Comcast from injecting their own RST packets into the stream, effectively killing the connection from both sides. Every time an ISP implements a harsh countermeasure, they force the evolution of the protocol. I see this simple as the next logical step in the constant pull and tug of P2P and ISP's. Still, kudos for these guys doing this stuff. I'm sure Blizzard will like hearing that their updates are hindered on Comcast's networks while P2P data has an easier time.

That doesn't sound possible. The actual RST flag is in the packet header, the payload is the only part that can be encrypted. You can't make a a connection selectively obey different parts of the TCP protocol. An ISP can kill any connection made over its network; making it difficult for them to identify torrent traffic is the only way to resist this.

Actually, IPSec will prevent the ISP from being able to reset the flow. If a packet comes in that is not signed/encrypted (depending on the mode) with the credentials of the other end-point, it is discarded as an attack. It's a pain to set up IPSec security associations in many conditions, but IKEv2 has made it somewhat better.

The fact that you are buying service from the attacker doesn't make them not an attacker. The counter measures developed to fight attackers may have limits, but they are there and are useful in this context.

This proposal does nothing to stop reset attacks. All it does is stop middle men capturing the peer list returned from the tracker. I don't believe comcast are snooping and using this information to identify torrent traffic. I say this because I have heard that applications like lotus notes are also affected by the injected reset packets. The only way to really defeat these injected resets is to use an IP protocol that is immune to forged packets. I believe SCTP encrypted and tunnelled over UDP packets woul

What about a version of TCP that doesn't have any reset packets?And then instead of a FIN packet, rely on the timeout.That isn't too big of a change, just comment out some code. It would mess with some routers, but the connections couldn't be stopped by a MitM attack.

Or something like TCP over UDP with those changes. SCTP sounds close, but that isn't encrypted at the transport layer, and is probably vulnerable to the same type of attack. It is different, so the Comcast forgery-throttling software doesn't at

I agree that normal browsing and P2P are going to look obviously different so hiding P2P within HTTP is not going to be too difficult to detect. However, P2P could look a lot like an FTP download. How's traffic analysis going to be able to tell the difference between a P2P movie download that looks like FTP from real and legit FTP?

I agree that normal browsing and P2P are going to look obviously different so hiding P2P within HTTP is not going to be too difficult to detect. However, P2P could look a lot like an FTP download. How's traffic analysis going to be able to tell the difference between a P2P movie download that looks like FTP from real and legit FTP?

In one case you have one or two connections to a single server. Traffic during a download will be in one direction only. In the other case you have connections to multiple destinations. There is significant traffic in both directions to each destination. Do those sound similar at all?

On my home Comcast segment, FTP uploads are filtered and shaped to hell, too. So are SSH and PPTP VPNs. And NNTP. I've got a big set of iptables rules to deal with what I can detect, but essentially if I'm doing anything but HTTP(S) or some kind of mail protocol, I can watch network latencies for all the traffic on my cable modem go up 500% and my bandwidth drop to about 20% of the real-world amount I normally have. I stop VPN-ing or NNTPing or torrenting and my connection goes back a few minutes later.

That may be true in some cases, but in this case, they are not defending against traffic analysis, which requires the ISP to maintain state about lots of data flows and analyse it in near-real time. If you look at what the BitTorrent devs are doing, they are obfuscating the peer list in the protocol, to prevent packet inspection from identifying the connection as BitTorrent. Interestingly, they are also intentionally using weak crypto (for performance reasons) - the goal being simply to raise the detectio

How do you know who has anything to hide, unless you search everyone?How do you know who is a terrorist, unless you search everyone?

You know after the fact, but it is impossible to preserve privacy and to know for sure "who has anything to hide". The people who wrote the constitution chose to err on the side of privacy. Now, we are choosing to err on the side of... no liberty.

You should consider a five-minute loop, rather than the youtube permanent, total record. You want to catch the cops weaving in and out of traffic at ludicrous speed with no lights on, leaving traffic waves or worse in their path. You don't want documentation of ten thousand slight exceedings of the speed limit, stops just over the line, rolling stops, and the myriad of other trivial things they could harass you with in retaliation;.

Indeed. This also helps with when you do have something to hide—if you only hide it when you have a reason to hide, then the act of hiding itself becomes a sign of guilt. But if you always hide it regardless of the reason (and the general populus does it also), then it allows due process to work as it always has: innocent until proven guilty.

And hopefully people will stop using Comcast if they do that. I think most users who don't use any p2p technology assume that Comcast isn't lying when they say they're throttling pirates, but if they start throttling everyone, they'll find most users will have a very negative response.

Yes, hopefully they will, because it makes life easier for the rest of us.

Why do you think Comcast is doing that? To annoy people? Because they are evil? They're doing it because a small number of people are eating up a lot of bandwidth and degrading service for the other users.

Comcast is trying to spin their actions as promoting fair use of the their networks. The truth is that ISP's profit from having data dumped INTO their network and have to pay hard cash for data LEAVING their network. By injecting RST's into the peers seeding traffic, they promote an asymmetric data flow that brings more data (and therefore money) into their network, while minimizing the money they have to pay other ISP's for data going out.
This proposal provides protection against the throttling of their upstream Bittorrent traffic only if the ISP is not aware of the info_hash of the torrent. Once this data is known it is possible to apply common data tagging and congestion control techniques to squelch this traffic. All the service provider (or application developers like SandVine) has to do is monitor the common torrent sites, and dynamically update this hashes into the network filters. This is sure to deny a majority of the torrent traffic out there (movies, linux distro's, etc).
Colin McNamara
CCIE #18233

And I for one, love it when Anonymous Cowards fight/call each other annoying little twats. I dunno, it just has this special feel to it. Like 2 invisible dudes throwing stuff at each other. Highly entertaining.

Uhm, only in the case of financial bilateral peering agreements. Don't misunderstand the overall problem - its financial - with other issues such as "network capacity", "available upstream bandwidth on the DOCSIS cable modem infrastructure" and similar issues.

Even massive amounts of P2P between their clients, not ever leaving their network, costs them money.

Adrian(No CCIE, but I've been working with SP networks of sorts since 1997.)

It had to come to a head at some point. ISPs have been bitching about P2P for a while now. Let's get those secret docs on "unlimited" usage out in the open. Let's define what is acceptable and let's give users the ability to meter their usage. My prediction is 95-99% of us won't be affected by these new open bandwidth policies and ISPs can go back into the business of providing dumb pipes.

They don't care about any protocol analysis. Any sufficiently long-lived, high volume, traffic flow between two IP addresses gets hit. I've had IPSEC VPN connections behave strangely and opened tickets, where the techs have admitted I had "accidentally" been flagged (IE, the IPSEC endpoints weren't on the whitelist, even though I have business class service).

The only way around this is to open multiple connections to different addresses, transfer small amounts per connection, and then shut it down, opening the next connection to a different endpoint. It requires a total reengineering of P2P, although the BitTorrent mechanism is closest to what would work.

What he said. I've also seen my IPSEC VPN connections get trashed. As for other encryption not helping, when I start an scp session uploading a file to my office I get 190KB/s. After a minute or two that rate is down to 40-45KB/s, and the entire network is punished. Other people here using the Internet can tell when I'm uploading something because the entire Internet connection is flogged to a crawl the same way we are when there's a torrent active.

Interestingly enough, this is actually quite close to how Freenet [freenetproject.org] works in its opennet mode. The turnover rate is probably rather low, but it has no non-encrypted protocol header and is constantly connecting to new nodes. With some tweaking it would be very hard to detect. IIRC it also already runs entirely over UDP, not TCP, which makes injecting RST packets impossible.

The only way around this is to open multiple connections to different addresses, transfer small amounts per connection, and then shut it down, opening the next connection to a different endpoint. It requires a total reengineering of P2P

Isn't that the very defenition of P2P to begin with? What needs reengineering about it?

Hey, don't shoot the messenger! I'm PAYING FOR BUSINESS CABLE. IE, my TOS says I CAN run servers, and I'm STILL Getting joe-jobbed.

We all need to band together and find a way to send a giant FU to these guys. How about a mass switch, at the end of the next quarter, to Verizon? Make them show a huge "surprise" to Wall Street and have to explain it in the context of their "net neutrality" position?

If they aren't already doing it (I dont know the exact technical details of what they are doing), ISPs like Comcast will simply start looking for anyone uploading large amounts of data (especially if they are uploading to a bunch of different people at once) and block that.

I'm surprised it took this long for the Bittorrent Devs to respond. Encryption is not a complete solution, as I have stated before, but it is a beginning. That is for certain.

It's going to get a lot more interesting from here on out. In the end, it will only benefit the consumers since they will receive technology that allows them to communicate a little more privately, and perhaps with a little luck, more anonymously too. One could only hope that TOR/Freenet technologies become as ubiquitous in their use as email. Perhaps a hybrid system with elements of Freenet, TOR, and Bittorrent all wrapped up into one would do the trick. I certainly think so.

I think, actually I know, that Comcast has fired the first shot in a losing battle.

I also just can't help pointing out the similarities to the Drug War. A million or so people in prison, and yet there are still plenty of users and suppliers. I would almost say it has effectively made no difference in the amount of people using drugs, or selling them. Especially, since the amount of drugs being sold and used in prisons is even higher then on the street.

So what is the point? If history has taught us anything, it is that governments (corporations even more so) will consistently fail at their attempts to limit/eliminate popular behavior. The elements may change from time to time, but the end result is always the same. The people will find a way to continue their behavior.

"Greetings, Professor Falken. Strange game. The only winning move is not to play."

The drug war has been costly to the people involved, but there is no doubt that it's made a difference. As the cost for any drug goes up, it's use goes down. Without hassling suppliers, and disrupting supply to some extent, the price would continue to go down, and there is no doubt that it's use would go up. Does it stop drug use ? Nope, never will. Prohibition doesn't work either, never has, never will. I'd rather see it legalized and taxed, and the proceeds used for voluntary treatment. But don't claim th

I think you may have missed my point. It has had an EFFECT. No one could argue that. However, when looking only at the number of users and suppliers, I would still state that there is practically no difference in the amount of users and suppliers before and after the Drug War. The price of course, has been greatly inflated to represent the added costs and risks associated the the supply side of this market.You say that as the cost of the drugs go up, the use goes down. Sounds quite logical, I must admi

Eating up crazy resources beyond the convections of a normal average daily internet regiment

ISP's are inundated with mass amounts of data chocking off more important services

I'm sorry, but you are dead wrong on that one. 100% Absolutely, Positively, Infinitely WRONG.
I hear a lot of people say that. I cannot possibly be wrong in my usage of my connection for the following reasons:

1) I pay for it.
2) It is unlimited.

unlimited (n-lm-td)
adj.
1. Having no restrictions or controls: an unlimited travel ticket.
2. Having or seeming to have no boundaries; infinite: an unlimited horizon.
3. Without qualification or exception; absolute: unlimited self-confidence.

They set those terms, not me. They have continually advertised a position that was in fact the opposite of their true intentions. All that matters is the contract here though, and that states unlimited.

I don't know if English is your first language, since your use of grammar is a little off, which I don't say in a negative way at all. I just don't understand what you mean by "convection".

You say "normal average daily internet regiment". That is in of itself, an observation only. It is meaningless to the discussion since it just a statistic. No one is actually bound by contract, or any verbal representations by any ISP that they must maintain a normal level of use. Unlimited means that you cannot apply any limitations on the usage; "Normal" is a limitation.

You also talk about more important services. There are no "more important services". Everybody is unlimited, therefore all traffic is equally unlimited. The ISP must therefore treat all traffic the same according to the representations of an unlimited contract.

Now if at some point in the future, the ISP offers for people to voluntarily apply QOS principles to their network traffic, that is in the best interests for everyone. I have no problem being asked, nicely, to apply a QOS tag to all my communications, as it only helps me in the end. I also like the idea of being nice and cooperating with my neighbor, so that under heavy load conditions, his VOIP sessions will get the priority he needs. The contracts could redone to reflect this in the future.

The point is to generate revenue by exploiting people's natural tendencies. Think of all the fines to be collected. The reconnection fees. The court fees. The jobs generated tracking torrent users. The training programs to be created to teach the fascists what they are looking for. Just like with the war on drugs, the point isn't to fix the problem. The point is to so fully integrate the "problem" into the system that it serves as a source of energy for and an excuse for the continued existence of the system itself.

One of the things I'm curious about is what kind of collateral damage this kind of thing does to legitimate traffic. Oddly enough, I couldn't get to expedia.com, transformers.com (hey, I have an eight-year-old), and store.apple.com when I first got Comcast. A couple of months later, when the news first broke that they were screwing with the traffic, those sites suddenly started working. Nothing changed at my house, and all of them started working at once.

Up until the last month or two, I've had Comcast with no BT filtering and everything was running fine. Up to 400KB/s down on good torrents. Poor upload, but exactly what the agreement stated at 6Mb/384Kb. Kept the upload from being saturated at 48 KB/s by capping it at 35-40 KB/s and web browsing still worked fine with it. Pinged at 35-50 ms while running BT.The past couple months, web browsing is unbearable while running BT with Comcast. As soon as I start it up, even at 15 KB/s upload, websites take 5-10

Happened a little later than I expected, but it still happened! Good work.

Ok so we have Britain proposing the monitoring of the entire internet, Australia is proposing an ISP-level filter, US cable companies are doing their own selective torrent throttling and various countries such as China already have expansive firewalls and filters in place. Even if this proposal falls through, or is modified somehow, I think we're going to have to accept that governments are in the pockets of the media companies and service providers will target users of p2p because, in their opinion, they aren't making as big a profit as they might like.

The next step is to ask what we, as the science, engineering and computer-loving community who have been using BitTorrent and various other protocols for legitimate uses before all the kids figured out they could score Amy Winehouse albums for free, can do to either circumvent the policies initiated by the above various groups or to bypass them completely.

Napster, Limewire and the first generation p2p clients collapsed so BitTorrent was designed and users flocked to it. Now it appears that BitTorrent is going to suffer the same fate (if not now than definitely in the near future - the increasing pressure put on ISP's and governments around the world by copyright holders is going to see to that).

We can't afford to fight fire with fire. Invasive laws and techniques used by companies such as Comcast may be un-Constitutional, or against the terms of service but the average p2p-user can't afford to launch a civil case against one of the biggest corporations in the USA. My suggestion is for a new protocol to be established, with the emphasis on sharing legitimate files such as patches, Linux ISO's, videos, game demo's etc. Inevitably the first people to jump onto the new system will be the true geeks (By this I mean your average Slashdotter) and by doing so, they can utilise it to its full extent (Something like the early days of BitTorrent) whilst the MPAA/RIAA flog a dead horse.

Of course it's only a matter of time before pirates jump onto the new protocol and then we watch the whole show unfold again. However p2p-users have proven resourceful and it's only a matter of time before yet another protocol is developed and the cycle continues. But the advantage lies with us. The cost to the developer of something like BitTorrent is minutely small when compared to the hundreds of millions of dollars MAFIAA throws away in its attempt to stop piracy. If we keep it up long enough we might finally get the message across that p2p != piracy, or we might simply bleed them dry.

Why does BitTorrent use TCP at all? If it used UDP, there would be many ways to detect and ignore forged packets.

Non-trivial applications are almost always better off managing their own connection state in my experience. A lot of TCP/IP networking code seems to be written to work around the quirks of TCP connections rather than to take advantage of them. UDP is clearly the better choice in cases like this.

Well currently the state of the art is in favor of encryption, rather than cryptanalysis, so I don't think that the advantage is automatically Comcast's. They could probably do some fairly sophisticated traffic analysis, but at the end of the day, they're not actually going to break the encryption and get at the contents, and they can't block all encrypted traffic because it's too critical for other purposes.

They can force the BitTorrent devs to produce a new version every few months, but in the long run I think they're on the losing end of the war -- if they want to stay in the data-transportation business, and assuming there aren't any major breakthroughs in cryptanalysis that render modern public-key technologies useless.

They control the connection. Unless you are using a Diffie-Hellman key exchange or other form of Perfect Forward Security, they can run a Man In the Middle attack. From my reading of this spec, it's still susceptible to MIM, ergo, you're still at the mercy of your carrier.

Comcast is killing the TCP/IP connection when talking to another peer, so that blocks cannot be exchanged. The connection to the tracker isn't overly important anyway, as you only rarely connect to it to get a random selection of new peers to connect to when needed. (And there are already ways to get these peers over UDP, most notably over the trackerless DHT extensions.)